Optimal Solution of O -line and On-line Generalized Caching

Network tra c can be reduced significantly if caching is utilized e ectively. As an e ort in this direction we study the replacement problem that arises in caching of multimedia objects. The size of objects and the cost of cache misses are assumed non-uniform. The non-uniformity of size is inherent in multimedia objects, and the non-uniformity of cost is due to the non-uniformity of size and the fact that the objects are scattered throughout the network. Although a special case of this problem, i.e. the case of uniform size and cost, has been extensively studied, the general case needs a great deal of study. We present a dynamic programming method of optimally solving the o -line and on-line versions of this problem, and discuss the complexity of this method.